Rhododendron plant named ‘ROBLET’

ABSTRACT

A new and distinct  Rhododendron  cultivar named ‘ROBLET’ is disclosed, characterized by distinctive coral colored semi double flowers with clear white margins. Plants are compact and bloom Spring, Summer and Fall. The new cultivar is a  Rhododendron , suitable for ornamental garden purposes.

Latin name of the genus and species: Rhododendron hybrid.

Variety denomination: ‘ROBLET’.

BACKGROUND OF THE INVENTION

The new cultivar is a product of selection by the inventor. This newvariety, hereinafter referred to as ‘ROBLET’, was discovered from aselection process involving two branch sports identified and selected byRobert Edward Lee Apr. 14, 2007 in Loxley, Ala., at a commercialnursery. The parent variety producing this naturally occurring mutationis Rhododendron ‘Roblen’ U.S. Plant Pat. No. 16,248, also invented byRobert Edward Lee. After identifying the two similar, but differentbranch mutations, the inventor confidentially evaluated and compared thetwo varieties over approximately two years. After confidential testingand evaluation, ‘ROBLET’ was selected by the inventor due to its morecompact plant growth, better flower form and better foliage.

The inventor first directed propagation of ‘ROBLET’ by vegetativecuttings on Jun. 20, 2007 at a commercial nursery in Loxley, Ala. Theinventor continued controlled testing and propagation, assessingstability of the unique characteristics of this variety. Multiplegenerations have been reproduced and have shown that the unique featuresof this cultivar are stable and reproduced true to type.

SUMMARY OF THE INVENTION

The cultivar ‘ROBLET’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, day length, and lightintensity, without, however, any variance in genotype. The followingtraits have been repeatedly observed and are determined to be the uniquecharacteristics of ‘ROBLET’ These characteristics in combinationdistinguish ‘ROBLET’ as a new and distinct Rhododendron cultivar:

-   -   1. Spring, summer, and fall blooming.    -   2. Unique flower coloring of coral with a clear white margin.    -   3. Single to semi-double flowers.    -   4. Compact plant habit.    -   5. Good specimen plant.    -   6. Excellent performance in planters.    -   7. Very good foundation plant.    -   8. Does well as an understory plant in a woodland garden.    -   9. Hardy to Zone 7.    -   10. Attracts butterflies.

COMPARISON TO PARENT VARIETY

‘ROBLET’ is similar in most horticultural characteristics to the parentvariety Rhododendron hybrid ‘ROBLEN’. Plants of the new cultivar‘ROBLET’ however, plants produce flowers that are distinctively coralwith a white margin, whereas flowers of ‘ROBLEN’ are solid red.Additionally, the mature plant height and spread of the new variety areless than that of the parent variety. Plant habit is overall morecompact in the new variety, compared to the parent.

COMMERCIAL COMPARISON

The inventor is not aware of any commercial varieties with semi double,coral and white colored flowers, with the unique re-bloomingcharacteristics of ‘ROBLET’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photograph in FIG. 1 illustrates in full color atypical plant of ‘ROBLET’ grown outdoors in Alabama. The plant isapproximately 2 years old, and is shown growing in the ground.

FIG. 2 illustrates in full color a close up of typical flowers of‘ROBLET’.

The photographs were taken using conventional techniques and althoughcolors may appear different from actual colors due to light reflectanceit is as accurate as possible by conventional photographic techniques.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart 2001 except where general terms ofordinary dictionary significance are used. The following observationsand measurements describe ‘ROBLET’ plants grown outdoors in Loxley, Ala.Plants are approximately 2 years old, in a 3 gallon nursery container.Measurements and numerical values represent averages of typical planttypes.

-   Botanical classification: Rhododendron hybrid ‘ROBLET’.

PROPAGATION

-   Typically by semi-hardwood cuttings in Spring and Summer.

PLANT

-   Growth habit: Compact evergreen shrub. Slow to moderate growth rate.-   Height: Approximately 35 cm to top of foliar and flowering plane.-   Plant spread: Approximately 70 cm.-   Branching characteristics: Well branched, approximately 20 primary    branches from center of plant, angled approximately 75° from center    of plant. Each primary branches has 4 to 10 lateral branches.-   Primary branches:    -   -   Length of primary branches.—Approximately 18 to 28 cm.        -   Diameter of primary branches.—Approximately 0.8 cm.        -   Primary branch strength.—Very strong, difficult to break.        -   Primary branch color.—Near RHS Yellow-Green N144D, with age,            becoming covered with a thin bark like layer colored near            Brown 200C.        -   Primary branch texture.—Young growth covered in appressed            hairs, approximately 0.15 cm long, colored near Brown 200B.            Older growth scaly, covered in appressed hairs colored near            White 155D.-   Lateral branches:    -   -   Number of lateral branches.—Approximately 8 to 20 per            primary branch.        -   Length of lateral branches.—Approximately 3 to 7 cm.        -   Diameter of lateral branches.—Average 0.35 cm.        -   Lateral branch strength.—Very strong, flexible.        -   Lateral branch color.—Near RHS Yellow-Green 144C.        -   Lateral branch texture.—Covered in moderately dense            appressed hairs, colored near RHS Brown 200B.-   Internode length: Range between 1.5 to 3.5 cm.-   Age of plant described: Approximately 2 years.

FOLIAGE

-   Leaf:    -   -   Type.—Simple.        -   Arrangement.—Alternate.        -   Average length.—Approximately 3.5 cm.        -   Average width.—Approximately 1.6 cm.        -   Shape of blade.—Narrow spatulate to obovate. Apex broader,            more spatulate on older foliage.        -   Apex.—Rounded, with a very shallow/short mucronate tip.        -   Base.—Broad attenuate.        -   Attachment.—Stalked.        -   Margin.—Entire.        -   Texture of top surface.—Leathery, slightly pubescent. Hairs            less than 1 mm.        -   Texture of bottom surface.—Glabrous, matte.        -   Foliage scent.—None.        -   Color.—Young foliage upper side: Near RHS Green 137B. Young            foliage under side: Near RHS Yellow-Green 144B. Mature            foliage upper side: Near RHS Green 137A, but darker. Mature            foliage under side: Near RHS Green 138B.        -   Venation.—Type: Pinnate. Venation color upper side: Near RHS            Yellow-Green 144B. Venation color under side: Near RHS            Yellow-Green 144C.        -   Petiole.—Length: About 1.2 cm. Diameter: About 0.3 cm.            Color: Near RHS Yellow-Green 144D, upper and lower surfaces.

FLOWER

-   Bloom period: Plants begin flowering, around late March, and    continue to produce flowers throughout Summer and Fall. Flowering    ends with frost, typically October or November.-   Flower:    -   -   Arrangement.—Single or semi double, perfect, open funnel            shaped.-   Peduncle:    -   -   Length.—Average 1.3 cm.        -   Diameter.—0.3 cm.        -   Color.—Near RHS Yellow-Green 145C, very faintly flushed with            Red 48C close to flower.        -   Texture.—Densely pubescent.        -   Aspect.—Straight to very slightly curved. Angle of            attachment, approximately 45° angle from stem.-   Flowers:    -   -   Length.—Average 5.0 cm.        -   Diameter.—Average 6.5 cm.        -   Facing direction.—Outwardly and upwardly facing.        -   Persistent or self-cleaning.—Petals self cleaning.        -   Fragrance.—Very faint.-   Tube:    -   -   Tube length.—Approximately 2.0 cm.        -   Tube width a widest point.—Approximately 2.2 cm.        -   Tube width and narrowest point.—Approximately 0.9 cm.-   Petals:    -   -   Unfused petal segments.—Length: Approximately 2.5 cm. Width:            Approximately 3.0 cm.        -   Apex.—Retuse.        -   Shape of petal.—Unfused portion, obovate.        -   Petal margin.—Entire to infrequent crenations. Ruffled            aspect along margin.        -   Petal arrangement.—Approximately ⅓ fused from base.        -   Petal number.—5.        -   Petal texture.—Smooth.        -   Color.—Upper surface at first opening: Near Red 53D. Under            surface at first opening: Near RHS Red52A. Inner surface at            maturity: Near RHS Red 50C, veins darker, near Red 53D.            Margins White N155C. Irregular small dots near Red-Purple            61B occasionally occur at the widest point in the throat.            Outer surface at maturity: Near RHS Red 48D, veins darker,            near Red 52A. Margin blotches near White N155C. Upper            surface at fading: Near RHS Red 55C, veins darker, near Red            54B. Margins White N155C. Irregular small dots near            Red-Purple 61B occasionally occur at the widest point in the            throat. Under surface at fading: Near RHS Red 49A, veins            darker, near Red 52B. Margin blotches near White N155C.-   Bud:    -   -   Shape.—Elliptic.        -   Length.—3 cm.        -   Diameter.—1.5 cm.        -   Color.—Near RHS Red 49A, blotched White N155C.-   Calyx/sepals:    -   -   Quantity per flower.—5 sepals.        -   Shape.—Narrow deltate.        -   Length.—0.5 cm.        -   Width.—0.3 cm.        -   Apex.—Acute.        -   Base.—Fused.        -   Margin.—Entire.        -   Texture.—Highly pubescent. Color: Inner Surface: Near RHS            Yellow-Green 145A. Outer Surface: Near RHS Yellow-Green            145B.

REPRODUCTIVE ORGANS

-   Stamens:    -   -   Number.—5.        -   Length.—4.0 cm.        -   Width.—0.1 cm.        -   Color.—Near RHS Red 49C.        -   Anthers.—Length: Approximately 0.3 cm. Color: Near RHS            Greyed-Orange 166B. Pollen: Not observed to date.-   Pistil:    -   -   Number.—1.        -   Length.—5 cm.        -   Style.—Length: 4.8 cm. Color: Near RHS Red-Purple 58B.        -   Stigma.—Globular, colored near Red-Purple 59A.        -   Ovary.—Sericeous texture. Approximately 0.2 cm in diameter.            Colored near Yellow-Green 147A. Hairs colored near White            N155D.

OTHER CHARACTERISTICS

-   Disease and pest resistance: Not observed to be susceptible nor    resistant to normal diseases and pests of Rhododendron.-   Temperature tolerance: USDA Zone 7.-   Fruit/seed production: Not observed to date.

What is claimed is:
 1. A new and distinct cultivar of Rhododendron plantnamed ‘ROBLET’ as herein illustrated and described.